Liquid manufacturing processes for panel layer fabrication

ABSTRACT

A method for manufacturing a light-emitting panel sandwiches a plurality of micro-components between two flexible substrates in a web configuration. Each micro-component contains a gas or gas-mixture capable of ionization when a sufficiently large voltage is supplied across the micro-component via at least two electrodes. The micro-components are disposed in sockets formed at pre-determined locations in a first dielectric substrate so that they are adjacent to electrodes imprinted in the first substrate. Dielectric layers and the conductors for acting as electrodes are formed using liquid processes or combined liquid and sheet processes, where liquid materials are applied to the surface of the underlying layer, then cured to complete the formation of layers. The assembled layers are coated with a protective coating and may include an RF shield. In one embodiment, patterning of the conductors is achieved by applying conductive ink using an ink jet process. In another embodiment, the conductors may be patterned photolithographically using a leaky optical waveguide as a contact mask.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 10/789,976,filed Mar. 2, 2004, now U.S. Pat. No. 7,025,648 entitled LiquidManufacturing Process for Panel Layer Fabrication, which is acontinuation of application Ser. No. 10/214,740, filed Aug. 9, 2002,entitled Liquid Manufacturing Processes for Panel Layer Fabrication, nowU.S. Pat. No. 6,764,367 which is a continuation-in-part of applicationSer. No. 09/697,344, filed Oct. 27, 2000, entitled A Light-EmittingPanel and Method for Making, now U.S. Pat. No. 6,612,889, and is relatedto the following co-owned, applications: Ser. No. 09/697,346, filed Oct.27, 2000 entitled: A Socket for Use with a Micro-Component in aLight-Emitting Panel, now U.S. Pat. No. 6,545,422; Ser. No. 09/697,358,filed Oct. 27, 2000, entitled: A Micro-Component for Use in aLight-Emitting Panel, now U.S. Pat. No. 6,762,566; Ser. No. 09/697,498,filed Oct. 27, 2000, entitled: A Method for Testing a Light-EmittingPanel and the Components Therein, now U.S. Pat. No. 6,620,012; Ser. No.09/697,345, filed Oct. 27, 2000, entitled: A Method and System forEnergizing a Micro-Component In a Light-Emitting Panel, now U.S. Pat.No. 6,570,335; Ser. No. 10/214,769, filed Aug. 9, 2002, entitled Use ofPrinting and Other Technology for Micro-Component Placement, now U.S.Pat. No. 6,796,867, filed herewith; Ser. No. 10/214,716, filed Aug. 9,2002, entitled Method of On-Line Testing of a Light-Emitting Panel, nowU.S. Pat. No. 6,935,913, filed herewith; Ser. No. 10/214,764, filed Aug.9, 2002, entitled Method and Apparatus for Addressing Micro-Componentsin a Plasma Display Panel, now U.S. Pat. No. 6,801,001, filed herewith;and Ser. No. 10/214,768, filed Aug. 9, 2002, entitled Design,Fabrication, Conditioning, and Testing of Micro-Components for Use in aLight-Emitting Panel, now U.S. Pat. No. 6,822,626, filed herewith. Eachof the above-identified applications is incorporated herein by referencein its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is relates to a method for manufacturing alight-emitting panel and more particularly to a web fabrication processfor manufacturing a light-emitting panel.

2. Description of Related Art

A number of different methods have been used or proposed forconstruction of plasma panel display devices in which a plasma-forminggas is enclosed between sets of electrodes which are used to excite theplasma. In one type of plasma display panel, wire electrodes are placedon the surfaces of parallel plates of glass so that they are spaceduniformly apart. The plates are then sealed together at the outer edgeswith the plasma forming gas filling the cavity formed between theparallel plates. Although widely used, this type of open displaystructure suffers from numerous disadvantages. The sealing of the outeredges of the parallel plates and the introduction of the plasma forminggas are both expensive and time-consuming processes, resulting in acostly end product. In addition, it is particularly difficult to achievea good seal at the sites where the electrodes are fed through the endsof the parallel plates, which can result in gas leakage and a shortenedproduct life. Another disadvantage is that individual pixels are notsegregated within the parallel plates. As a result, gas ionizationactivity in a selected pixel during a write operation may spill over toadjacent pixels, thereby raising the undesirable prospect of possiblyigniting adjacent pixels. Even if adjacent pixels are not ignited, theionization activity can change the turn-on and turn-off characteristicsof the nearby pixels.

In another type of known plasma display, individual pixels aremechanically isolated either by forming trenches in one of the parallelplates or by adding a perforated insulating layer sandwiched between theparallel plates. These mechanically isolated pixels, however, are notcompletely enclosed or isolated from one another because there is a needfor the free passage of the plasma forming gas between the pixels toassure uniform gas pressure throughout the panel. While this type ofdisplay structure decreases spill over, spill over is still possiblebecause the pixels are not in total electrical isolation from oneanother. In addition, in this type of display panel it is difficult toproperly align the electrodes and the gas chambers, which may causepixels to misfire. As with the open display structure, it is alsodifficult to get a good seal at the plate edges. Furthermore, it isexpensive and time consuming to introduce the plasma producing gas andseal the outer edges of the parallel plates.

In yet another type of known plasma display, individual pixels are alsomechanically isolated between parallel plates. In this type of display,the plasma forming gas is contained in transparent spheres formed of aclosed transparent shell. Various methods have been used to contain thegas filled spheres between the parallel plates. In one method, spheresof varying sizes are tightly bunched and randomly distributed throughouta single layer, and sandwiched between the parallel plates. In a secondmethod, spheres are embedded in a sheet of transparent dielectricmaterial and that material is then sandwiched between the parallelplates. In a third method, a perforated sheet of electricallynonconductive material is sandwiched between the parallel plates withthe gas filled spheres distributed in the perforations.

While each of the types of displays discussed above are based ondifferent design concepts, the manufacturing approach used in theirfabrication is generally the same: a batch fabrication process. It wouldbe desirable to simplify and streamline the manufacturing process and toeliminate at least a portion of the steps which can have a negativeimpact on process yield and/or cost. The present invention is directedto such a method.

BRIEF SUMMARY OF THE INVENTION

According to the present invention, a novel flexible plasma displaypanel and methods for making such a panel involve a web fabricationprocess. In this display panel, the plasma forming gas is sealed intransparent micro-components formed of a closed transparent shell. Themicro-components, which may be spheres, capillaries or virtually anyother three-dimensional shape, are then coated with phosphors to emitone of the primary colors: red, green or blue. In the web fabricationprocess, a nonconductive flexible first substrate has electrodesimprinted thereon using known printing techniques, such as lithographyor screen printing. In one variation, dimples are embossed in the firstsubstrate to define locations at which micro-components are to be placedrelative to the electrodes. In another variation, the micro-componentsare electrostatically drawn to the correct locations relative to theelectrodes. After affixing the micro-components in place, and possiblytesting to ensure complete and proper placement of the micro-components,a second substrate, also in web form, is disposed over the firstsubstrate so that the micro-components are sandwiched between the firstand second substrates. Additional electrodes may be patterned on thesecond substrate, and the second substrate may be applied as more thanone layer to create one or more dielectric/electrode sandwiches near themicro-component to provide additional sustain electrodes or addressingelectrodes. Alternatively, the second substrate can be preformed withembedded electrodes which are then aligned with the micro-componentswhen the second substrate is applied. A protective layer may be placedon top of the second substrate, then the layered assembly is diced toform individual light-emitting panels of the desired size.

In a second embodiment of the present invention, a light-emitting panelis formed on a first substrate comprising a flexible web material. Aconductive film is patterned on the first substrate to define aplurality of electrodes and dimples are formed to define locations inwhich gas-filled micro-components, which emit light when excited, are tobe located. An adhesive material may be deposited into the dimples. Themicro-components are then applied to fill the dimples, where they areheld in place by the adhesive. Application of the micro-components tothe first substrate can be achieved by a number of different methodsincluding use of a drop tower or an ink-jet type dispenser, or byrunning the first substrate through a shaker bath filled with an excessof micro-components. An electrostatic charge may be applied to the firstsubstrate to draw the micro-components to the desired locations. Afterthe micro-components are affixed to the first substrate, a liquiddielectric material is applied to the surface of the first substrateusing known methods such a vacuum or atmospheric coating, which mayinclude chemical vapor deposition (CVD), plasma sputtering,electron-beam deposition, injection of coating fluid under pressure,screen printing or similar processes. The conditions under which theliquid dielectric are applied, e.g., the surface energy and surfacetension of the liquid, are selected to ensure good wetting of themicro-components, i.e., so that the dielectric material is in contactwith the surfaces of the micro-components without bubbles or gaps.Further, the liquid dielectric should be applied with a uniformthickness across the first substrate so that the spacing between theexcitation electrodes is uniform across the display. Depending on thedeposition process that was used, the liquid dielectric is then cured toremove any solvents and other volatile agents that were included in theliquid to facilitate fluid delivery, leaving the micro-componentsembedded in the flexible, cured dielectric layer. In a preferredembodiment, the liquid dielectric is coated so as to form a dielectriclayer with a thickness corresponding to about half the height of themicro-component, allowing a mid-plane conductor to be formed near themicro-components.

Electrodes are formed by applying a conductive liquid to the uppersurface of the dielectric layer. The electrodes may be patterned usingknown lithographic methods, e.g., conductive film deposition,photoresist deposition, masked exposure and development of thephotoresist followed by etching to remove the unprotected film, or byprinting, e.g., ink-jet printing with a conductive ink. In analternative embodiment, conductive liquids that are selectively drawn tothe desired locations using one or more characteristics of the liquidincluding surface tension, viscosity, thickness and electricalconductivity in combination with surface characteristics of thedielectric layer. For example, where channels or depressions in thedielectric layer may act as guides for distribution of a liquidconductor to the desired locations near the micro-components, so that noalignment is required in the step for forming the electrodes.

A second application of liquid dielectric material coats the uppersurface of the previous dielectric layer, mid-plane conductor and thesurfaces of the micro-components above the mid-plane point. Anadditional sequence of depositing a liquid dielectric and a patternedconductive film may be added before “topping off” the layers with afinal coating of liquid dielectric to form a layer that approaches, butnot does not cover, the tops of the micro-components. A protective coverlayer is then placed over top of the entire assembly, then the panelsare diced into the desired dimensions. The cover layer is preferably aweb material that may be applied according to known web manufacturingmethods.

In an alternate method for patterning of electrodes usingphotolithographic methods, after formation of a conductive layer, acoating of photosensitive material, e.g., photoresist, is disposed ontop of the conductive layer. A contact mask is formed using a flexibleoptical waveguide having a surface area which covers all or asignificant portion of the light-emitting panel. During formation of thewaveguide, the cladding material is patterned to allow light to escapefrom the waveguide at selective locations corresponding to locations ofthe electrodes to be defined. The photoresist is exposed at the desiredlocations by light “leaking” from the waveguide, then the waveguide maskis removed. After the photoresist is cured and the unexposed resist isremoved, the conductive material is selectively etched to form theelectrodes at the desired locations.

Other features, advantages, and embodiments of the invention are setforth in part in the description that follows, and in part, will beobvious from this description, or may be learned from the practice ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of this invention willbecome more apparent by reference to the following detailed descriptionof the invention taken in conjunction with the accompanying drawings.

FIG. 1 is a perspective view of a portion of a light-emitting panelshowing the basic socket structure of a socket formed from patterning asubstrate, as disclosed in an embodiment of the present invention.

FIG. 2 a is a perspective view of a portion of a light-emitting panel,partially cut-away, to reveal micro-components and electrodes.

FIG. 2 b is a detail view of the embodiment of FIG. 2 a with upperdielectric layers cut away to reveal the co-planar sustainingelectrodes.

FIG. 3 a is a diagrammatic cross-sectional view of a portion of anembodiment of the light-emitting panel with the electrodes having amid-plane configuration.

FIG. 3 b is a perspective view of the embodiment of FIG. 3 a with theupper dielectric layer cut away to reveal the uppermost sustainelectrode.

FIG. 4 is a diagrammatic cross-sectional view of a portion of anembodiment of the light-emitting panel with the electrodes having aconfiguration with two sustain and two address electrodes, where theaddress electrodes are between the two sustain electrodes.

FIG. 5 is a diagrammatic cross-sectional view of a portion of anembodiment of the light-emitting panel with the electrodes having aco-planar configuration.

FIG. 6 is a diagrammatic cross-sectional view of a portion of anembodiment of the light-emitting panel with the electrodes having amid-plane configuration.

FIG. 7 is a diagrammatic cross-sectional view of a portion of anembodiment of the light-emitting panel with the electrodes having aconfiguration with two sustain and two address electrodes, where theaddress electrodes are between the two sustain electrodes.

FIG. 8 is a flowchart of a first embodiment of a web fabrication methodfor manufacturing light-emitting displays according to the presentinvention.

FIG. 9 is a graphical representation of a web fabrication process formanufacturing light-emitting panels according to the first embodiment ofthe web fabrication method.

FIG. 10 is a flow diagram of a second embodiment of a web fabricationmethod according to the present invention.

FIG. 11 is an exploded perspective view of a portion of a light-emittingpanel showing the basic socket structure of a socket formed by disposinga plurality of material layers with aligned apertures on a substratewith the electrodes having a co-planar configuration.

FIG. 12 shows an exploded perspective view of a portion of alight-emitting panel showing the basic socket structure of a socketformed by disposing a plurality of material layers with alignedapertures on a substrate with the electrodes having a mid-planeconfiguration.

FIG. 13 shows an exploded view of a portion of a light-emitting panelshowing the basic socket structure of a socket formed by disposing aplurality of material layers with aligned apertures on a substrate withelectrodes having a configuration with two sustain and two addresselectrodes, where the address electrodes are between the two sustainelectrodes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As embodied and broadly described herein, the preferred embodiments ofthe present invention are directed to a novel method for making alight-emitting panel. In particular, preferred embodiments are directedto web fabrication processes for manufacturing light-emitting panels.

FIG. 1 illustrates an exemplary display panel in which a plurality ofsphere-shaped micro-components 40 are embedded within a sandwich ofdielectric layers consisting of first substrate 10 and second substrate20. The first substrate 10 is formed from a flexible sheet material thatis appropriate for web fabrication, such as polyester (e.g., Mylar®),polyimide (e.g., Kapton®), polypropylene, polyethylene, propylene, nylonor any polymer-based material possessing dielectric propertiesappropriate for use as an insulator between electrodes as needed foroperation of a plasma display panel. Such electrical requirements areknown to those of skill in the art. Second substrate 20 may be made fromthe same or similar dielectric material.

The first substrate 10 includes a plurality of sockets 30 adapted forretaining at least one micro-component 40. The sockets 30 may bedisposed in any pattern, having uniform or non-uniform spacing betweenadjacent sockets. Patterns may include, but are not limited to, auniform array, alphanumeric characters, symbols, icons, or pictures.Preferably, the sockets 30 are disposed in the first substrate 10 sothat the distance between adjacent sockets 30 is approximately equal.Sockets 30 may also be disposed in groups such that the distance betweenone group of sockets and another group of sockets is approximatelyequal. This latter approach may be particularly relevant in colorlight-emitting panels, where each group of sockets represents acombination of the primary colors: red, green and blue.

Multiple micro-components may be disposed in a socket to provideincreased luminosity and enhanced radiation transport efficiency. In acolor light-emitting panel according to one embodiment of the presentinvention, a single socket supports three micro-components configured toemit red, green, and blue light, respectively. The micro-components 40may be of any shape, including, but not limited to, spherical,cylindrical, and aspherical. In addition, it is contemplated that amicro-component 40 includes a micro-component placed or formed insideanother structure, such as placing a spherical micro-component inside acylindrical-shaped structure. In a color light-emitting panel accordingto an embodiment of the present invention, each cylindrical-shapedstructure holds micro-components configured to emit a single color ofvisible light or multiple colors arranged red, green, blue, or in someother suitable color arrangement.

In one embodiment, the micro-components 40 are positioned in the sockets30 of first substrate 10 by use of an ink-jet-type feeder which providesaligned placement of the micro-components 40. A number of methods ofplacing the micro-components in the sockets are disclosed in co-pendingapplication Ser. No. 10/214,769 now U.S. Pat. No. 6,796,867, which isincorporated herein by reference in its entirety.

An adhesive or bonding agent, discussed below, may be applied to eachmicro-component to assist in placing/holding a micro-component 40 orplurality of micro-components in a socket 30. In an alternativeembodiment, an electrostatic charge is placed on each micro-componentand an electrostatic field is applied to each micro-component to assistin the placement of a micro-component 40 or plurality ofmicro-components in a socket 30. This technique, known as “electrostaticsheet transfer” (“EST”) is described in the aforementioned co-pendingapplication Ser. No. 10/214,769 now U.S. Pat. No. 6,796,867. Applying anelectrostatic charge to the micro-components also helps avoidagglomeration among the plurality of micro-components. In one embodimentof the present invention, an electron gun may be used to place anelectrostatic charge on each micro-component, then one electrodedisposed proximate to each socket 30 is energized to provide theopposing electrostatic field required to attract the electrostaticallycharged micro-component.

In order to assist in placing/holding a micro-component 40 or pluralityof micro-components in a socket 30, a socket 30 may contain a bondingagent or an adhesive. The bonding agent or adhesive, typically anelectrically-conductive epoxy material which is filled with, forexample, silver, copper, aluminum, or other conductor, may be applied tothe inside of the socket 30 by differential stripping, lithographicprocess, sputtering, laser deposition, chemical deposition, vapordeposition, or preferably, by deposition using ink jet technology. Oneskilled in the art will recognize that other methods of coating theinside of the socket 30 may be used.

In its most basic form, each micro-component 40 includes a shell 50filled with a plasma-forming gas or gas mixture 45. Any suitable gas orgas mixture 45 capable of ionization may be used as the plasma-forminggas, including, but not limited to, krypton, xenon, argon, neon, oxygen,helium, mercury, and mixtures thereof. In fact, any noble gas could beused as the plasma-forming gas, including, but not limited to, noblegases mixed with cesium or mercury. Further, rare gas halide mixturessuch as xenon chloride, xenon fluoride and the like are also suitableplasma-forming gases. Rare gas halides are efficient radiators havingradiating wavelengths over the approximate range of 190 nm to 350 nm,i.e. longer than that of pure xenon (147 to 170 nm). Using compoundssuch as xenon chloride that radiates near 310 nm results in an overallquantum efficiency gain, i.e., a factor of two or more, given by themixture ratio. Still further, in another embodiment of the presentinvention, rare gas halide mixtures are also combined with otherplasma-forming gases as listed above. This description is not intendedto be limiting. One skilled in the art would recognize other gases orgas mixtures that could also be used. In a color display, theplasma-forming gas or gas mixture 45 is chosen so that during ionizationthe gas will produce a specific wavelength of light corresponding to adesired color. For example, neon-argon emits red light, xenon-oxygenemits green light, and krypton-neon emits blue light. While aplasma-forming gas or gas mixture 45 is used in a preferred embodiment,any other material capable of luminescing is also contemplated, such asan electro-luminescent material, organic light-emitting diodes (OLEDs),or an electrophoretic material.

The shell 50 may be made from a wide assortment of materials, including,but not limited to, silicates, polypropylene, glass, any polymeric-basedmaterial, magnesium oxide and quartz and may be of any suitable size.The shell 50 may have a diameter ranging from micrometers to centimetersas measured across its minor axis, with virtually no limitation as toits size as measured across its major axis. For example, acylindrical-shaped micro-component may be only 100 microns in diameteracross its minor axis, but may be hundreds of meters long across itsmajor axis. In a preferred embodiment, the outside diameter of theshell, as measured across its minor axis, is from 100 microns to 300microns. In addition, the shell thickness may range from micrometers tomillimeters, with a preferred thickness from 1 micron to 10 microns.

When a sufficiently large voltage is applied across the micro-componentthe gas or gas mixture ionizes forming plasma and emitting radiation.The potential required to initially ionize the gas or gas mixture insidethe shell 50 is governed by Paschen's Law and is closely related to thepressure of the gas inside the shell. In the present invention, the gaspressure inside the shell 50 ranges from tens of torrs to severalatmospheres. In a preferred embodiment, the gas pressure ranges from 100torr to 700 torr. The size and shape of a micro-component 40, and thetype and pressure of the plasma-forming gas contained therein, influencethe performance and characteristics of the light-emitting panel and areselected to optimize the panel's efficiency of operation.

There are a variety of coatings 300 and dopants that may be added to amicro-component 40 that also influence the performance andcharacteristics of the light-emitting panel. The coatings 300 may beapplied to the outside or inside of the shell 50, and may eitherpartially or fully coat the shell 50. Types of outside coatings include,but are not limited to, coatings used to convert UV light to visiblelight (e.g. phosphor), coatings used as reflecting filters, and coatingsused as band-gap filters. Types of inside coatings include, but are notlimited to, coatings used to convert UV light to visible light (e.g.phosphor), coatings used to enhance secondary emissions and coatingsused to prevent erosion. Those skilled in the art will recognize thatother coatings may also be used. The coatings 300 may be applied to theshell 50 by differential stripping, lithographic processes, sputtering,laser deposition, chemical deposition, vapor deposition, or depositionusing ink jet technology. In a preferred embodiment, the coating isapplied by immersing the micro-components in a slurry of phosphorparticles, similar to the procedures used in the manufacture offluorescent lamps, so that the particles adhere to the outer surface ofthe micro-component. One skilled in the art will recognize that othermethods of coating the inside and/or outside of the shell 50 may beused. Types of dopants include, but are not limited to, dopants used toconvert UV light to visible light (e.g. phosphor), dopants used toenhance secondary emissions and dopants used to provide a conductivepath through the shell 50. The dopants are added to the shell 50 by anysuitable technique known to one skilled in the art, including ionimplantation. It is contemplated that any combination of coatings anddopants may be added to a micro-component 40. Alternatively, or incombination with the coatings and dopants that may be added to amicro-component 40, a variety of coatings may be coated on the inside ofa socket 30. These coatings include, but are not limited to, coatingsused to convert UV light to visible light, coatings used as reflectingfilters, and coatings used as band-gap filters.

In an embodiment of the light emitting panel, when a micro-component isconfigured to emit UV light, the UV light is converted to visible lightby at least partially coating the inside the shell 50 with phosphor, atleast partially coating the outside of the shell 50 with phosphor,doping the shell 50 with phosphor and/or coating the inside of a socket30 with phosphor. In a color panel, according to an embodiment of thepresent invention, colored phosphor is chosen so the visible lightemitted from alternating micro-components is colored red, green andblue, respectively. By combining these primary colors at varyingintensities, all colors can be formed. It is contemplated that othercolor combinations and arrangements may be used. In another embodimentfor a color light-emitting panel, the UV light is converted to visiblelight by disposing a single colored phosphor on the micro-component 40and/or on the inside of the socket 30. Colored filters may then bealternatingly applied over each socket 30 to convert the visible lightto colored light of any suitable arrangement, for example red, green andblue. By coating all the micro-components with a single colored phosphorand then converting the visible light to colored light by using at leastone filter applied over the top of each socket, micro-componentplacement is made less complicated and the light-emitting panel is moreeasily configurable.

Additional coatings may be applied or modifications made to themicro-component to enhance performance, for example, by increasingluminosity and radiation transport efficiency, and to permitconstruction of a DC light-emitting panel. Luminousity can be improvedby at least partially coating the micro-component with a secondaryemission enhancement material such as magnesium oxide and thulium oxide.Alternatively or in conjunction with the coating, the shell can be dopedwith a secondary emission enhancement material. The micro-component canalso be coated with or have a doped shell to enhance emission and/orradiation transport with reflective or conductive materials. Doping theshell 50 with a conductive material such as silver, gold, platinum oraluminum provides a direct conductive path to the gas or gas mixturecontained in the shell. Also, an index matching material may be used toselect a pre-determined emission wavelength, i.e., providing a bandpassfilter.

The size and shape of the socket 30 influence the performance andcharacteristics of the light-emitting panel and are selected to optimizethe panel's efficiency of operation. In addition, socket geometry may beselected based on the shape and size of the micro-component to optimizethe surface contact between the micro-component and the socket and/or toensure connectivity of the micro-component and any electrodes disposedwithin the socket. Further, the size and shape of the sockets 30 may bechosen to optimize photon generation and provide increased luminosityand radiation transport efficiency. For example, the size and shape maybe chosen to provide a field of view with an angle that can be madewider or narrower as needed for a specific application. That is to say,the cavity may be sized, for example, so that its depth subsumes amicro-component deposited in a socket, or it may be made shallow so thata micro-component is only partially disposed within a socket.Alternatively, in another embodiment of the present invention, the fieldof view may be set to a specific angle by disposing on the secondsubstrate at least one optical lens. The lens may cover the entiresecond substrate or, in the case of multiple optical lenses, arranged soas to correspond with each socket. In another embodiment, the opticallens or optical lenses are configurable to adjust the field of view ofthe light-emitting panel.

In an embodiment for a method of making a light-emitting panel includinga plurality of sockets, a cavity is formed, or patterned, in a substrate10 to create a basic socket 30, such as illustrated in FIG. 1. Thecavity may be formed in any suitable shape and size by any combinationof physically, mechanically, thermally, electrically, optically, orchemically deforming the substrate. Disposed proximate to, and/or in,each socket 30 may be a variety of enhancement materials 325, as shownin FIG. 3 a. The enhancement materials 325 include, but are not limitedto, anti-glare coatings, touch sensitive surfaces, contrast enhancement(black mask) coatings, protective coatings, transistors,integrated-circuits, semiconductor devices, inductors, capacitors,resistors, control electronics, drive electronics, diodes, pulse-formingnetworks, pulse compressors, pulse transformers, and tuned-circuits.

Still referring to FIG. 3 a, a socket 30 is formed by stacking aplurality of material layers 60 a–d to form the first substrate,disposing at least one electrode either directly on the top of the firstsubstrate, within the material layers or any combination thereof, andselectively removing a portion of the material layers 60 a–d to create acavity. The material layers 60 a–d include any combination, in whole orin part, of dielectric materials, metals, and enhancement materials 325,as discussed above. The placement of the material layers 60 may beaccomplished by any transfer process, photolithography, sputtering,laser deposition, chemical deposition, vapor deposition,xerographic-type processes, plasma deposition, or deposition using inkjet technology. One of general skill in the art will recognize otherappropriate methods of disposing a plurality of material layers on asubstrate. The socket 30 may be formed in the combination of layers 60a–d using any of a variety of methods on the layers, either individuallyor combined, including, but not limited to, wet or dry etching,photolithography, laser heat treatment, thermal form, mechanical punch,embossing, stamping-out, drilling, electroforming or by dimpling.

Using FIG. 5 to illustrate, in an alternate method of forming a socket30, a cavity 55 is formed in a first substrate 10, then a plurality ofmaterial layers 65 a,b is disposed over the first substrate 10 so thatthe material layers 65 a,b conform to the cavity 55. At least oneelectrode is formed on the first substrate 10, within the materiallayers 65, or any combination thereof. In the example of FIG. 5,electrode 80 is formed on the first substrate, while electrodes 70 and75 are disposed within the layers. The cavity may be formed in anysuitable shape and size by any combination of physically, mechanically,thermally, electrically, optically, or chemically deforming thesubstrate. The material layers 65 a,b include any combination, in wholeor in part, of dielectric materials, metals, and enhancement materials325, as described previously. The placement of the material layers 65a,b may be accomplished by any transfer process, photolithography,sputtering, laser deposition, chemical deposition, vapor deposition,xerographic-type processes, plasma deposition, coating with a liquid ordeposition using ink jet technology. One of general skill in the artwill recognize other appropriate methods of disposing a plurality ofmaterial layers on a substrate.

In yet another alternative method of forming a socket, at least oneelectrode is disposed on the first substrate, within the materiallayers, or any combination thereof. Each of the material layers includesa preformed aperture that extends through the entire material layer. Theapertures may be of the same size or may be of different sizes, e.g.,they may be graduated in size to create the socket with a tapered orcurved profile. The plurality of material layers are sequentiallydisposed on top of the first substrate with the apertures in alignmentthereby forming a cavity. The material layers include any combination,in whole or in part, of dielectric materials, metals, and enhancementmaterials, as described previously. The placement of the material layersmay be accomplished by any transfer process, photolithography,sputtering, laser deposition, chemical deposition, vapor deposition,xerographic-type processes, plasma deposition, or deposition using inkjet technology. One of general skill in the art will recognize otherappropriate methods of disposing a plurality of material layers on asubstrate.

In the above-described methods of making a socket in a light-emittingpanel, disposed in, or proximate to, each socket may be at least oneenhancement material. As stated above the enhancement material 325 mayinclude, but is not limited to, anti-glare coatings, touch sensitivesurfaces, contrast enhancement (black mask) coatings, protectivecoatings, transistors, integrated-circuits, semiconductor devices,inductors, capacitors, resistors, control electronics, driveelectronics, diodes, pulse-forming networks, pulse compressors, pulsetransformers, and tuned-circuits. In a preferred embodiment of thepresent invention, the enhancement materials may be disposed in, orproximate to each socket by any transfer process, photolithography,sputtering, laser deposition, chemical deposition, vapor deposition,xerographic-type processes, plasma deposition, deposition using ink jettechnology, or mechanical means. In another embodiment of the presentinvention, a method for making a light-emitting panel includes disposingat least one electrical enhancement (e.g. the transistors,integrated-circuits, semiconductor devices, inductors, capacitors,resistors, control electronics, drive electronics, diodes, pulse-formingnetworks, pulse compressors, pulse transformers, and tuned-circuits),in, or proximate to, each socket by suspending the at least oneelectrical enhancement in a liquid and flowing the liquid across thefirst substrate. As the liquid flows across the substrate the at leastone electrical enhancement will settle in each socket. It iscontemplated that other substances or means may be use to move theelectrical enhancements across the substrate. One such means mayinclude, but is not limited to, using air to move the electricalenhancements across the substrate. In another embodiment of the presentinvention the socket is of a corresponding shape to the at least oneelectrical enhancement such that the at least one electrical enhancementself-aligns with the socket.

The electrical enhancements may be used in a light-emitting panel for anumber of purposes including, but not limited to, lowering theionization potential of the plasma-forming gas in a micro-component,lowering the voltage required to sustain/erase the ionization charge ina micro-component, increasing the luminosity and/or radiation transportefficiency of a micro-component, and augmenting the frequency at which amicro-component is activated or illuminated. In addition, the electricalenhancements may be used in conjunction with the light-emitting paneldriving circuitry to alter the power requirements necessary to drive thelight-emitting panel. For example, a tuned-circuit may be used inconjunction with the driving circuitry to allow a DC power source topower an AC-type light-emitting panel. In an embodiment of the presentinvention, a controller is provided that is connected to the electricalenhancements and capable of controlling their operation. Having theability to individually control the electrical enhancements at eachpixel/subpixel provides a means by which the characteristics ofindividual micro-components may be altered/corrected after fabricationof the light-emitting panel. These characteristics include, but are notlimited to, luminosity and the frequency at which a micro-component islit. One skilled in the art will recognize other uses for electricalenhancements disposed in, or proximate to, each socket in alight-emitting panel.

The electrical potential necessary to energize a micro-component 40 issupplied via at least two electrodes. In a general configuration, thelight-emitting panel includes a plurality of electrodes, wherein atleast two electrodes are adhered to either the first substrate or thesecond substrate, or at least one electrode is adhered to each of thefirst substrate and the second substrate and wherein the electrodes arearranged so that voltage applied to the electrodes causes one or moremicro-components to emit radiation. In another general configuration, alight-emitting panel includes a plurality of electrodes, wherein atleast two electrodes are arranged so that voltage supplied to theelectrodes causes one or more micro-components to emit radiationthroughout the field of view of the light-emitting panel withoutcrossing either of the electrodes.

In an embodiment where the sockets 30 are patterned on the firstsubstrate 10 so that the sockets are formed in the first substrate, atleast two electrodes may be disposed on the first substrate 10, thesecond substrate 20, or any combination thereof. In the exemplaryembodiment shown in FIG. 1, a sustain electrode 70 is disposed on orwithin the second substrate 20 and an address electrode 80 is disposedon or within the first substrate 10. As illustrated, address electrode80 is positioned in the first substrate 10 so that it is at least partlydisposed within the socket.

Methods for distributing the micro-components into the sockets includedispensing the micro-components using a placement tool, an ink jet-typeprinter, or a gravity-fed drop tower which is aligned with the socketsin the substrate. Alternatively, the substrate may be passed through oneor more vibratory, e.g., ultrasonic, shaker baths containing an excessplurality of micro-components, i.e., a much larger number ofmicro-components than are needed to fill the available positions on thesubstrate. Such shakers are well known in the art and may includeorbital shakers and other vibratory movements. The shaking causes themicro-components to be dispersed across the surface of the substrate sothat a micro-component is disposed within each of the sockets. A furtherdiscussion of different methods for placement of the plurality ofmicro-components is provided in the aforementioned co-pendingapplication Ser. No. 10/214,769 now U.S. Pat. No. 6,796,867.

In an embodiment of the light emitting panel where the first substrate10 includes a plurality of material layers 60 and the sockets 30 areformed within the material layers, at least two electrodes may bedisposed on the first substrate 10, disposed within the material layers60, disposed on the second substrate 20, or any combination thereof. Inone embodiment, as shown in FIG. 2 a, a first address electrode 80 isdisposed within the material layers 60, a first sustain electrode 70 isdisposed within the material layers 60, and a second sustain electrode75 is disposed within the material layers 60, such that the firstsustain electrode and the second sustain electrode are in a co-planarconfiguration. FIG. 2 b is a cut-away of FIG. 2 a showing thearrangement of the co-planar sustain electrodes 70 and 75. In anotherembodiment, as shown in FIG. 3 a, a first sustain electrode 70 isdisposed on the first substrate 10, a first address electrode 80 isdisposed within the material layers 60, and a second sustain electrode75 is disposed within the material layers 60, such that the firstaddress electrode is located between the first sustain electrode and thesecond sustain electrode in a mid-plane configuration. FIG. 3 b is acut-away of FIG. 3 a showing the first sustain electrode 70. As seen inFIG. 4, in a preferred embodiment of the light emitting panel, a firstsustain electrode 70 is disposed within the material layers 60, a firstaddress electrode 80 is disposed within the material layers 60, a secondaddress electrode 85 is disposed within the material layers 60, and asecond sustain electrode 75 is disposed within the material layers 60,such that the first address electrode and the second address electrodeare located between the first sustain electrode and the second sustainelectrode.

In an embodiment where a cavity 55 is patterned on the first substrate10 and a plurality of material layers 65 are disposed on the firstsubstrate 10 so that the material layers conform to the cavity 55, atleast two electrodes may be disposed on the first substrate 10, at leastpartially disposed within the material layers 65, disposed on the secondsubstrate 20, or any combination thereof. In one embodiment, as shown inFIG. 5, a first address electrode 80 is disposed on the first substrate10, a first sustain electrode 70 is disposed within the material layers65, and a second sustain electrode 75 is disposed within the materiallayers 65, such that the first sustain electrode and the second sustainelectrode are in a co-planar configuration. In another embodiment, asshown in FIG. 6, a first sustain electrode 70 is disposed on the firstsubstrate 10, a first address electrode 80 is disposed within thematerial layers 65, and a second sustain electrode 75 is disposed withinthe material layers 65, such that the first address electrode is locatedbetween the first sustain electrode and the second sustain electrode ina mid-plane configuration. As seen in FIG. 7, in a preferred embodimentof the present invention, a first sustain electrode 70 is disposed onthe first substrate 10, a first address electrode 80 is disposed withinthe material layers 65, a second address electrode 85 is disposed withinthe material layers 65, and a second sustain electrode 75 is disposedwithin the material layers 65, such that the first address electrode andthe second address electrode are located between the first sustainelectrode and the second sustain electrode.

In an embodiment where a plurality of material layers 66 with alignedapertures 56 are disposed on a first substrate 10 thereby creating thecavities 55, at least two electrodes may be disposed on the firstsubstrate 10, at least partially disposed within the material layers 65,disposed on the second substrate 20, or any combination thereof. In oneembodiment, as shown in FIG. 11, a first address electrode 80 isdisposed on the first substrate 10, a first sustain electrode 70 isdisposed within the material layers 66, and a second sustain electrode75 is disposed within the material layers 66, such that the firstsustain electrode and the second sustain electrode are in a co-planarconfiguration. In another embodiment, as shown in FIG. 12, a firstsustain electrode 70 is disposed on the first substrate 10, a firstaddress electrode 80 is disposed within the material layers 66, and asecond sustain electrode 75 is disposed within the material layers 66,such that the first address electrode is located between the firstsustain electrode and the second sustain electrode in a mid-planeconfiguration. As seen in FIG. 13, in a preferred embodiment of thelight emitting panel, a first sustain electrode 70 is disposed on thefirst substrate 10, a first address electrode 80 is disposed within thematerial layers 66, a second address electrode 85 is disposed within thematerial layers 66, and a second sustain electrode 75 is disposed withinthe material layers 66, such that the first address electrode and thesecond address electrode are located between the first sustain electrodeand the second sustain electrode.

The specification, above, has described, among other things, variouscomponents of a light-emitting panel and methodologies to make thosecomponents and to make a light-emitting panel. In an embodiment of thepresent invention, it is contemplated that those components may bemanufactured and those methods for making may be accomplished as part ofweb fabrication process for manufacturing light-emitting panels. Inanother embodiment of the present invention, a web fabrication processfor manufacturing light-emitting panels includes the steps of providinga first substrate, disposing micro-components on the first substrate,disposing a second substrate on the first substrate so that themicro-components are sandwiched between the first and second substrates,and dicing the first and second substrate “sandwich” to form individuallight-emitting panels. In another embodiment, the first and secondsubstrates are provided as rolls of material. A plurality of sockets mayeither be preformed on the first substrate or may be formed in and/or onthe first substrate as part of the web fabrication process. Likewise,the first and second substrates may be pre-formed so that the firstsubstrate, the second substrate or both substrates include a pluralityof electrodes. Alternatively, a plurality of electrodes may be disposedon or within the first substrate, on or within the second substrate, oron and within both the first substrate and second substrate as part ofthe web fabrication process. It should be noted that where suitable,fabrication steps may be performed in any order. It should also be notedthat the micro-components may be preformed or may be formed as part ofthe web fabrication process. In another embodiment, the web fabricationprocess is performed as a continuous high-speed inline process with theability to manufacture light-emitting panels at a rate faster thanlight-emitting panels manufactured as part of batch process.

As illustrated in FIGS. 8 and 9, in an embodiment of the presentinvention, the web fabrication process includes the following processsteps: First, a micro-component forming process 800 is performed tocreate the micro-component shells 50 and fill the micro-components withplasma-forming gas 45. A micro-component coating process 810 follows inwhich the micro-components are coated with phosphor 300 or any othersuitable coatings, producing a plurality of coated and filledmicro-components 400. In a preferred embodiment, coating of themicro-components is achieved by immersing the micro-components in aslurry of phosphor particles, allowing the phosphor particles to adhereto the outer surface. Afterwards, the micro-components are processedthrough a curing step to remove the solvents that were used to createthe slurry. A circuit and electrode printing process 820 prints at leastone electrode and any needed driving and control circuitry on a firstsubstrate 420. Patterning process 840 is performed to create a pluralityof cavities on a first substrate to provide a plurality of sockets 430.Generally, this step involves applying pressure and possibly heat todeform the substrate material and create a plurality of dimples in thesubstrate. Micro-component placement process 850 places at least onecoated and filled micro-component 400 in each socket 430, resulting in afirst substrate assembly 440 comprising micro-components 400 in sockets430 on the first substrate 10. If required, an electrode printingprocess 860 prints at least one electrode on a second flexible substrate20 to produce a second substrate with electrodes 410. Second substrateapplication and alignment process 870 aligns the second substrate 410over the first substrate assembly 440 so that the micro-components aresandwiched between the first substrate and the second substrate asassembly 450. Panel dicing process 880 cuts through the assembly 450 toyield individual light-emitting panels 460.

The process flow for an alternate embodiment of the web fabricationmethod is illustrated in FIG. 10. As in the previously-describedembodiment, the first substrate is a flexible dielectric material, whichin step 200 is fed from a payout reel, to which a plurality ofmicro-components is applied, either by aligned placement with sockets(dimples) and/or adhesive spots formed in/on the first substrate, or bypassing the first substrate with adhesive spots through a shaker bathfilled with micro-components, as discussed above.

According to the exemplary process flow, electrodes and other circuitryare printed on the flexible substrate (step 202), typically using anink-jet process, then sockets are formed (204). It should be noted thatthese steps may be performed in reverse order, i.e., the sockets may beformed prior to patterning the electrodes. Conductive adhesive isapplied to the sockets (206) using an ink jet-type printer.Alternatively, if may be possible to combine steps 204 and 206 byinjecting adhesive through the tool used to create the dimple in thesubstrate material.

Micro-components, which were separately formed in step 208 are placed inthe sockets using an appropriate method as described in theafore-mentioned co-pending application Ser. No. 10/214,769 now U.S. Pat.No. 6,796,867. As previously described, the micro-components aretypically coated with a phosphor material for visible light emission. Inan exemplary embodiment of micro-component forming process step 208, themicro-components are coated with phosphor by immersing themicro-components in a bath containing a slurry of phosphor particles sothat the particles adhere to the micro-component surface. Themicro-components are then removed from the slurry and subjected to acuring process, e.g., a furnace, oven or other heat source, to removeany solvents that were used to form the slurry, leaving a solid phosphorcoating on the micro-component surface.

In step 212, the adhesive material that holds the micro-component inplace is cured by applying heat for a pre-determined time (based uponthe manufacturer's recommendations), or at room temperature for a longertime (again, based on the manufacturer's specifications), introducingpressurized gas or other known adhesive curing method, then, thedielectric film is applied in liquid form by coating the substrate witha liquid dielectric material (step 214). The liquid dielectric materialmay be a polyimide (e.g., Kapton®), or other polymeric materials.

Application of liquid dielectric uses known techniques of web coatingusing web coating systems such as those commercially available fromRolltronics (Menlo Park, Calif.), Sheldahl, Inc. (Northfield, Minn.),Frontier Industrial Technology, Inc. (Towanda, Pa.) and Applied FilmsCorp. (Longmont, Colo.), among others. An exemplary coating systemcomprises a web-handling machine mounted inside a large vacuum chamber.The machine unwinds a web from a payoff reel, wraps it over a drum,which may be temperature-controlled to assist in film formation, andwinds it onto a take-up reel. Each reel is driven indirectly via chaindrive and a DC motor, allowing better control of web speed whiledeveloping a higher tension than would be possible with a motor and gearreduction box. The signal from an optical encoder is delivered to aprocess controller for speed control of one motor, and a measurement ofthe length unwound. The other motor is operated in regenerative mode todevelop holdback tension. An exemplary deposition process for a coatingstack of films comprises positioning the drum over a first depositiondevice, e.g., sprayer or evaporator. A fixed length of web is unwound inthe first pass to deposit the first film. Then the motor direction isreversed, and a second film is deposited in a second pass. Next the drummay be moved sideways to position it over a second deposition device,which may be, e.g., a sprayer, evaporator, or ink jet head. The webdirection is reversed a third time and the third coating is deposited ina single pass. In each case, web speed is determined according to thedesired coating thickness and deposition rate. An alternativeconfiguration includes one or more accumulators disposed between thepayoff and take-up reels which allows sections of the web to dwell incertain stations along the processing line, for example, for depositionor curing a film for an extended period of time, without requiring allother steps in the process to pause or interfering with the tension ofthe web.

The dielectric film may be applied as a thin film using chemical vapordeposition (CVD), plasma CVD, or other vapor deposition methods,sputtering, or may be applied as a liquid “paint” such as one of theroll coat methods used in the coating of magnetic recording media. See,e.g., U.S. Pat. No. 6,322,010, the disclosure of which is incorporatedherein by reference in its entirety. In the preferred embodiment, aliquid process is used to create a film on the order of 100 microns withrelatively tight tolerances across the film, e.g., ±1%. The viscosity ofthe dielectric material in its liquid form is selected to ensurecomplete wetting of the surfaces of the micro-components to the extentthat the micro-components should be covered, and to ensure uniformity ofthe film thickness. The key parameter to be observed in formation of thedielectric film is the uniformity of the dielectric properties so thatthe surface flashover (voltage breakdown that occurs on or above thesurface of an insulator) and bulk dielectric breakdown characteristicsare tightly controlled to minimize the possibility of arcing or voltagebreakdown across any dielectric discontinuities when voltage is appliedto electrodes corresponding to a given micro-component. A typical gooddielectric material has a breakdown voltage in the range of 500 to 5000volts per mil (about 200 to 2000 kV/cm) in the bulk, with a preferredrange of 1000 volts per mil (400 kV/cm) or higher. The surface flashoverfield strength should also be in the range of 1000 volts per mil (400kV/cm). This will be achieved partially through material selection andprincipally with the application of a thin coating, such as a resin orepoxy, to the surfaces of the electrodes and micro-component. Thiscoating inhibits electron flow over the surface between the electrodesthereby raising its flashover voltage. In addition, a good loss tangentfor the dielectric material, typically in the range of 0.01 to 0.1, at100 kHz to 1 MHz is preferred. An exemplary range for dielectricconstant in this frequency range is 3.5 to 5.

Wetting can be enhanced by the inclusion of surfactants in the liquiddielectric material to manage the surface energy of the liquid.Alternatively, or in addition, surfactants may also be applied to theouter surface of the micro-components to facilitate complete wetting.Obtaining a uniform thickness of the dielectric film can be furtherfacilitated by use of a scraper or knife edge which is preciselypositioned over the drum to remove any excess thickness as the webmaterial leaves the drum.

Viscosity and surface tension of the liquid dielectric may also becontrolled to produce a positive, neutral, or negative meniscus aroundeach micro-component. In one embodiment, a negative meniscus results ina surface depression abutting the micro-component

The dielectric material is then cured (step 216) to form a uniform filmat least partially covering the micro-components, embedding them inplace within the combination of the first substrate and the dielectriclayer formed using the liquid dielectric. Curing is typically achievedby passing the web material through a heated chamber set to atemperature appropriate for curing the dielectric film. As the liquiddielectric is typically a commercially-available product, thetemperature and duration of the curing step will be based upon themanufacturer's recommendations for the selected liquid material. As willbe apparent to those of skill in the art, some variation of therecommended curing conditions may be incorporated for compatibility withthe particular web manufacturing equipment or process that is beingused. The portion of web material to be cured may be paused or slowed bythe use of an accumulator, or the heated chamber may have a lengthdesigned to provide a sufficient duration within the chamber while theweb material moves at a predetermined speed, or a combination of thetwo.

In the preferred embodiment, a portion of the micro-component is leftexposed after curing of the dielectric film. Considering the embodimentof FIG. 5 as an example, the first application of liquid dielectricresulted in a dielectric layer 65 a that covers just under one-half theheight of the micro-component 50.

Electrodes are formed by applying a conductive liquid to the uppersurface of the second substrate (step 218). The electrodes may bepatterned using known lithographic techniques, e.g., conductive filmdeposition over the entire area, photoresist deposition, masked exposureand development followed by etching, or by printing, e.g., ink-jetprinting, or by using liquids that are selectively drawn to the desiredlocations using one or a combination of characteristics of the liquidincluding surface tension, viscosity, thickness and electricalconductivity. In the preferred embodiment, a conductive ink is appliedusing an ink-jet printing technique. The ink contains copper, indiumoxide, silver, or other conductive material carried in an epoxy orepoxy-like material. Appropriate conductive inks are commerciallyavailable and will have electrical conductivity in the range of 1250mhos/cm or higher. After printing, the conductive ink is cured based onthe manufacturer's recommendations (step 220).

In an alternate embodiment, the characteristics of the liquid dielectricmaterial from which the dielectric layer is formed can be selected tocreate a shallow trough or depression connecting the micro-components ina line, e.g., a negative meniscus is formed upon deposition or a smallamount of shrinkage can occur during curing to create the depression.The conductive liquid used to form the electrodes is selected with aviscosity and thickness such that it will be drawn into the depressionsto fill them, thus creating a conductive line running between themicro-components. It is important, however, that the conductive film notstick to the micro-components themselves. Therefore, the liquidconductor should include a component to prevent wetting of themicro-component surface. An additional step in this alternate embodimentcan be to scrape away any excess conductor from the surface of thedielectric layer except where it has filled the depressions. Forexample, a squeegee or other scraper can be used to level the outersurface of the assembly so that the conductor is flush with the outersurface of the dielectric layer. After deposition of the conductivefilm, an appropriate curing step is performed, generally according tospecifications provided by the material manufacturer.

If an unpatterned conductive film has been deposited, i.e., a solidlayer of conductive film is produced, the film can be patterned usingconventional photolithographic methods in which a photoresist layer isformed on top of the conductive film, the photoresist is exposed througha mask bearing the desired electrode pattern, the photoresist isdeveloped so that the desired electrode pattern remains, the conductoris selectively etched away using chemical or plasma etching, and theremaining photoresist is then stripped, leaving behind the patternedelectrodes. Other forms of patterning are known to those of skill in theart, including e-beam writing or laser ablation.

In an alternate method for formation of electrodes usingphotolithographic methods, after formation of a conductive layer, acoating of photosensitive material, e.g., photoresist, is deposited ontop of the conductive layer. A contact mask is provided which is formedfrom a flexible optical waveguide having a wide surface area whichcovers all or a significant area of a section of the web material. Anexemplary waveguide device is described in U.S. Pat. No. 6,091,874,which is incorporated herein by reference in its entirety. The waveguidematerial is patterned so that the index of refraction of its cladding isselectively increased so that it “leaks” at positions corresponding tothe desired locations of the electrodes to be defined. Light, typicallyfrom a laser light source or a high intensity lamp, of an appropriatewavelength for exposure of the photoresist is coupled into the waveguideusing conventional coupling means. The flexible waveguide is alignedwith the underlying pattern over the area of photoresist-coatedconductive layer on which the pattern is to be formed. The photoresistis then exposed by the light emitted from the selective leaks in thewaveguide. After the photoresist is cured and the unexposed resist isremoved, the conductive material is selectively etched to form theelectrodes at the desired locations.

In embodiments of the device in which multiple layers of conductors arerequired, see, e.g., the embodiments of FIGS. 5–7, after curing and, ifrequired, patterning, the conductive film to form the electrodes,another deposition of liquid dielectric is performed as described aboveby passing the web material through the liquid dielectric depositionprocess. After formation of a second dielectric layer, another step isperformed to create additional electrodes. Referring to FIG. 7 toillustrate, dielectric layers 65 a, 65 b and 65 c alternate with secondaddress electrode 85, first address electrode 80 and first sustainelectrode 70, respectively, such that the web manufacturing processincludes three separate steps for depositing liquid dielectric to formthe dielectric layers and three separate steps for depositing aconductive liquid to form the electrodes.

After formation of the final (uppermost) electrodes, a protective layer,e.g., layer 20 in FIG. 7, is applied, either using a liquid dielectricuniformly coated over the assembly, or a flexible sheet materiallaminated over the top of the light-emitting panel assembly. If a liquidis used, the assembly must again be processed through the appropriatecuring step (224). Then, the panels are cut to the desired size in thedicing step (226).

In one embodiment, prior to applying the top layer in step 222, anoptional contrast enhancement layer may be included in which themicro-components are surrounded by a dark, preferably black, backgroundfield. One method for applying this black mask layer includes coatingthe area surrounding the micro-components, i.e., the dielectric layerand conductive lines, with a slurry of carbon black particles (step 219)or a similar black curable liquid. The coating can be applied by uniformapplication of the slurry to the upper surface of the assembly, thenusing a squeegee to remove the material from the micro-components.Alternatively, the slurry can be applied using an ink jet-type printer,with the printer target being aligned to selectively apply the slurry tocreate a ring or other pattern surrounding each micro-component. Afterdeposition of the coating, a curing step is performed to dry the blackmask layer by removing solvents used to make the slurry. In yet anotheralternative method for formation of the black mask layer, after curingof the carbon black slurry, a photolithographic process can be used toselectively etch the black film from the surface of themicro-components.

In another alternate embodiment of the web manufacturing process, ahybrid sheet/liquid process is used. As described with regard to thefirst embodiment of the web manufacturing process shown in FIG. 9, asecond substrate is applied as a sheet material, where openings areformed in the second substrate to correspond to the locations of themicro-components. However, in this embodiment, the openings are not astightly toleranced to fit the micro-components, but are larger, thusrequiring less precision in the alignment of the openings to themicro-components. Then, a liquid dielectric with dielectriccharacteristics close to or matching those of the second substratematerial is applied by an ink-jet process, or may be coated over theentire surface. If coated over the entire surface, the use of a scraperor squeegee will assist in forcing the liquid into the spaces betweenthe micro-components and the inside edges of the second substrateopenings. The viscosity and surface energy of the liquid dielectricmaterial are selected to wet the surfaces of the micro-components andfile any gaps between the second substrate and the micro-components.After curing, a continuous dielectric film surrounds themicro-components as in the previous-described embodiments.

In yet another embodiment, after formation of the protective layer (step224) and before dicing, an RF screen is formed by depositing aconductive liquid over the entire top surface of the assembly, where theconductive liquid is clear or becomes clear when cured. For example,indium-tin-oxide (ITO) can be used, however, other transparentconductive coatings are known, including transparent gold (TPG) andtransparent silver or aluminum-based coatings. It may be desirable tocoat an additional protective dielectric layer over RF screen, which maybe performed using a liquid dielectric material followed by curing, orby applying a sheet of dielectric materials over the assembly. Inaddition to use as a RF screen, transparent conductive materials can beused in the construction of the light-emitting displays so as tofacilitate implementation as a heads-up display for use in motorvehicles for purposes of facilitating a driver's ability to readdisplays without diverting his or her eyes away from the road.

Other embodiments and uses of the present invention will be apparent tothose skilled in the art from consideration of this application andpractice of the invention disclosed herein. The present description andexamples should be considered exemplary only, with the true scope andspirit of the invention being indicated by the following claims. As willbe understood by those of ordinary skill in the art, variations andmodifications of each of the disclosed embodiments, includingcombinations thereof, can be made within the scope of this invention asdefined by the following claims.

1. A method for manufacturing a light-emitting panel comprising:providing a first substrate, the first substrate having a plurality offirst conductors formed thereon; disposing at least one micro-componentof a plurality of micro-components at each of a plurality of firstlocations on the first substrate corresponding to the plurality ofconductors, each micro-component adapted to emit radiation in responseto electrical excitation; electrically isolating the plurality ofmicro-components from each other; and depositing a conductive film at aplurality of second locations adapted to interact with the firstconductors to excite one or more selected micro-components.
 2. Themethod of claim 1, wherein each of the micro-components are coated witha phosphor material.
 3. The method of claim 2, wherein the phosphormaterial is applied to the micro-components by immersing themicro-components in a slurry of phosphor particles, then curing aphosphor coating formed on the micro-components.
 4. The method of claim1, further comprising depositing an RF screen over the conductive film.5. The method of claim 1, further comprising: photolithographicallypatterning the conductive film to form the second conductors.
 6. Themethod of claim 5, wherein the step of photolithographically patterningcomprises selectively exposing a photosensitive material by contactingthe photosensitive material with a leaky optical waveguide.
 7. Themethod of claim 1, wherein the first substrate has a plurality ofdimples formed therein, wherein one dimple is formed at each of theplurality of first locations.
 8. The method of claim 7, wherein anadhesive material is applied within each of the plurality of dimples forsecuring the micro-component in the dimple.
 9. The method of claim 1,wherein depositing a conductive film at a plurality of second locationsincludes deposition of a conductive liquid and curing of the conductiveliquid.
 10. The method of claim 9, wherein deposition of a conductiveliquid includes inkjet printing.
 11. The method of claim 1, whereinelectrically isolating the plurality of micro-components from each othercomprises deposition and curing of a liquid dielectric material.
 12. Themethod of claim 11, wherein the liquid dielectric material includes asurfactant.
 13. The method of claim 1, wherein disposing at least onemicro-component of a plurality of micro-components at each of aplurality of first locations comprises applying an electrostatic chargeto the first substrate to draw the micro-components to the firstlocations.
 14. The method of claim 1, wherein disposing at least onemicro-component of a plurality of micro-components at each of aplurality of first locations comprises running the first substratethrough a shaker bath filled with an excess of micro-components.
 15. Amethod for forming a flexible light emitting panel comprising: feeding afirst substrate material from a payout reel into a web coating machine;printing a first plurality of electrodes on the first substratematerial; forming a plurality of sockets at a plurality of locations inthe first substrate material; disposing at least one micro-component ineach socket of the plurality of sockets; applying a first dielectricmaterial over the first substrate material, the first plurality ofelectrodes, and at least a portion of each micro-component of theplurality of micro-components; and printing a second plurality ofelectrodes over the first dielectric material.
 16. The method of claim15, further comprising applying an adhesive material within each of theplurality of sockets for securing the at least one micro-component inthe socket.
 17. The method of claim 15, wherein disposing at least onemicro-component in each socket of the plurality of sockets comprisesusing electrostatic sheet transfer to place each micro-component into anappropriate socket.
 18. The method of claim 15, wherein printing asecond plurality of electrodes comprises inkjet printing.
 19. The methodof claim 15, wherein the dielectric material is a liquid and has asurface tension adapted to provide a uniform thickness across the firstsubstrate.
 20. The method of claim 19, wherein the liquid dielectricmaterial includes a surfactant.
 21. The method of claim 15, furthercomprising applying a second dielectric material over the over thesecond plurality of electrodes.
 22. The method of claim 21, furthercomprising, applying a third plurality of electrodes over the seconddielectric material.
 23. The method of claim 15, wherein themicro-components are coated with a phosphor material.
 24. The method ofclaim 23, wherein the phosphor material is applied to themicro-components by immersing the micro-components in a slurry ofphosphor particles, then curing a phosphor coating formed on themicro-components.
 25. The method of claim 15, wherein disposing at leastone micro-component of a plurality of micro-components at each of aplurality of first locations comprises running the first substratematerial through a shaker bath filled with an excess ofmicro-components.
 26. A method for forming a flexible light emittingpanel comprising: feeding a first dielectric substrate material from apayout reel in a web coating machine; printing a first plurality ofelectrodes on the first dielectric material; forming a plurality ofsockets at a plurality of locations in the first dielectric material;disposing at least one micro-component in each socket of the pluralityof sockets; aligning a second sheet of material over the firstdielectric substrate material and the first plurality of electrodes,wherein the second dielectric sheet material has a plurality of openingstherein corresponding to the plurality of locations, the plurality ofopenings having diameters sized to allow the at least onemicro-component to pass therethrough; applying a dielectric materialover at least a portion of the second sheet material; and printing asecond plurality of electrodes over the second sheet material.